Vehicle rollover —generally defined as vehicular accident in which a vehicle turns over on its side or roof —is an extremely dangerous form of a vehicle crash. Vehicle rollover accidents while relatively rare —estimated at approximately 3% of all vehicle crashes —account for a disproportionately high number of fatal crashes —estimated at approximately 31% of all fatal vehicle crashes. The Nation Highway Transportation Safety
Administration (NHTSA) reported that 10,666 people were killed in the US in vehicle rollover crashes in 2002. Many factors are involved in a vehicle rollover including for instance vehicle center of gravity, vehicle suspension stiffness, vehicle tire traction, etc. However, according to Wikipedia, “The main cause for rolling over is turning too sharply while moving too fast” (see Appendix A, page 1, first paragraph). While there may be several factors for a vehicle to be turned or steered beyond the vehicle threshold of roll such as driver hurry or impatience and driver inexperience, a well know cause for excessive turning or steering to the point of vehicle roll is the occurrence of an object such as a tumble weed or squirrel suddenly appearing in the drivers path (hereafter referred to Sudden Object Appearance or SOA). In such SOA, even the most experienced drivers can feel the inherent and immediate urge to rapidly turn the steering wheel. It is just such turning of the steering wheel that causes many vehicle rollovers.
In recent years, a system commonly referred to as Electronic Stability Control or ESC has, by automatically selectively apply torque or braking force to certain of a vehicles wheels, been used in significantly improving stability of vehicles, especially when such vehicles would have otherwise “spun out” or “fish-tailed” when cornering. However, such ESC systems, which typically require complex rollover prediction schemes, cannot prevent vehicle rollover when a vehicle steering wheel is turned too sharply for the vehicle speed as in a SOA situation. Further, a number of inventions dealing with vehicle steering control have been developed over the years. However, such inventions have typically merely dealt with preventing damage to a driving surface (i.e. turf) or prevention of a power steering system, and no such systems are known to prevent vehicle rollover, especially in a SOA situation. Examples of such inventions are provided in the following list of US patents and applications, the whole of which are incorporated herein by reference: U.S. Pat. Nos. 5,489,006, 6,584,388, 6,588,799, 6,714,848, 6,954,140, 7,107,136, 7,261,303, 7,325,644, 7,440,844, 7613,555, 20030055549, 20030088349, 20030093201, 20040102894, 20040104066, 20040215384, 20050060069, 20050110227, 20060030991, 20060129298, 20060162987, 20070299583, 20080133101, 20090228173, 20100191423, and 20110060505.